Mounting for phonograph tone arms



. March 3, 964 w. R. HAWKINS 3,123,332

MOUNTING FOR PHONOGRAPH TONE ARMS Filed Nov. 14, 1960 WHHHHHHHH-' INVENTOR. Mun/w R. HAWK/N5 W/Zzm United States Patent 3,123,332 MOUNTING FOR PHONOGRAPH TONE ARMS. William R. Hawkins, Panorama City, Calif., assignor to Newcornb Electronics Corp., Los Angeles, Calif., a corporation of California Filed Nov. 14, 1960, Ser. No. 69,198 Claims. (Cl. 248-358) This invention relates to phonographs and especially to those using tone arms adapted to cooperate with a sound groove.

Sound record grooves of this character now quite commonly carry undulations not only on the side walls, but also hill and dale undulations on the bottom of the grooves. Primarily such records are especially adapted for stereo sound reproduction. In order that the needle may faithfully follow both sets of undulations, the tone arm is preferably supported in a resilient manner and yet with such gentle touch that the wear on the grooves is minimized. A restricted universal movement for the arm is permitted.

it is one of the objects of this invention to provide an improved mounting for the tone arm. By the aid of this invention, the needle accurately follows the groove patterns.

In order to provide the resilience, a long tubular guide is used, supported by the aid of rubber collars on a stationary support. It is another object of this invention to make it possible to predetermine the resilient force produced by the collars.

It is still another object of this invention to ensure against sustained mechanical oscillation of the tone arm that may be engendered by its resilient mounting.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of one embodiment of the invention. For this purpose, there is shown a form in the drawings accompanying and forming a part of the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a fragmentary plan view of a phonograph structure in which the invention is incorporated;

FIG. 2 is an enlarged sectional View, taken along a plane corresponding to line 2-2 of FIG. 1, the tone arm being shown in elevation; and

FIG. 3 is a fragmentary View, taken from the bottom of FIG. 2.

In FIG. 1 there are indicated a turntable 1 and a tone arm 2. The tone arm 2 is shown in inactive position, as resting upon a support 3.

The tone arm 2 is mechanically mounted on the upper enlarged head 4- of a post 5 in a convenient manner. One element 6 of the mounting collar is illustrated. Since the specific tone arm structure forms no part of this invention further description thereof is unnecessary.

The post 5 extends through a hollow stud 7 having a head 8. The post 5 is rotatable within the stud 7, which is resiliently supported, as hereinafter described, upon the upper wall 9 of the phonograph cabinet.

The mounting for the stud 7 includes a pair of sleeve 3,123,332 Patented Mar. 3, 1964 members 10 and 11 through which the stud 7 passes with limited clearance. Each of the sleeve members has attached thereto a rubber collar 12 or 13. Interposed between the collars 12 and 13 is a damping member 14, of felt or the like, and formed as a compressible washer.

As shown most clearly in FIG. 2, the two sleeve members 10 and 11 are urged together against a ring 15 by the aid of a nut 16'. :By proportioning the length of the sleeve members 10 and 11, the degree of compression of collars 12 and 13 can be controlled.

The length of the ring 15 is chosen in such a way as to dispose the tone arm 2 at an appropriate level, and may be interchanged in order to adjust this level.

The outer ends of the sleeve assembly 10-11 are outwardly bent so as to provide an appropriate seat with the lower end of the ring 15 and with the upper surface of the nut 16.

The mounting for the collars 12 and 13 includes a pair of metal rings 17 and 18. These metal rings form spaced flanges. They each have an extension 19 or 20, which are adjacent each other, to provide ears for the passage of fastening means, such as rivets 21, for attaching the structure to the cover member 9.

The rings 17 and 18 have inwardly directed edges 22 and 23 that are inclined toward each other and engage appropriate slots in the resilient collars 12 and 13.

The rings 17 and 18 are sufficiently resilient so as to be appropriately stressed by tightening of the nut 16.

Movement of the post 5 in any direction is resiliently resisted by the collars 12 and 13. Furthermore, rapid oscillations of the tone arm 2 are damped out by the felt member 14. The adjustment of the resilient force can be readily accomplished by proper choice of the length of the sleeve members 19 and 11. The shorter these sleeve members, the greater the compression of collars 12 and 13. Nevertheless, the sleeve structure 10-11 provides a sufiiciently long guide to limit lateral movement of the support structure.

The inventor claims:

1. In a resilient mounting: a two-part sleeve; a pair of spaced resilient collars respectively mounted on the two parts of the sleeve; a damping member interposed between the collars; means for drawing the sleeve parts together to compress the damping member between the collars; said sleeve parts having end flanges for causing the collars to be also compressed; and a support passing through the sleeve parts.

2. In a resilient mounting: a sleeve; spaced resilient collars mounted on the outer periphery of the sleeve; a damping member between the collars and compressed thereby; means for mounting the collars; a support passing throught the sleeve, comprising a threaded member having a shoulder opposed to one end of the sleeve; a ring interposed between said one end and the shoulder; and a nut engaging the threads of the threaded member and the opposite end of the sleeve.

3. In combination: a pair of contiguous sleeve members; collars carried respectively by the members and made from resilient material; a clamping member clamped between the collars; and a ring having spaced flanges, said flanges respectively having edge portions inclined toward each other and received in grooves on the exterior of the collars.

4. The combination as set forth in claim 3 in which the spaced flanges are flexible so as to permit compression of the collars.

5. In a resilient mounting: a sleeve; spaced resilient collars mounted on the outer periphery of the sleeve; 21 compressible damping member between the collars and compressed thereby; means for mounting the collars comprising a pair of rings surrounding the collars and having inner edges inclined toward each other and embedded respectively in the collars; and a support passing through the sleeve.

References fitted in the file of this patent UNITED STATES PATENTS Carlson Sept. 15, 1942 Jones Oct. 5, 1943 Efromson Aug. 2, 1949 Barber June 10, 1952 Hutton Oct. 11, 1955 

1. IN A RESILIENT MOUNTING: A TWO-PART SLEEVE; A PAIR OF SPACED RESILIENT COLLARS RESPECTIVELY MOUNTED ON THE TWO PARTS OF THE SLEEVE; A DAMPING MEMBER INTERPOSED BETWEEN THE COLLARS; MEANS FOR DRAWING THE SLEEVE PARTS TOGETHER TO COMPRESS THE DAMPING MEMBER BETWEEN THE COLLARS; SAID SLEEVE PARTS HAVING END FLANGES FOR CAUSING THE COLLARS TO BE ALSO COMPRESSED; AND A SUPPORT PASSING THROUGH THE SLEEVE PARTS. 